The present invention pertains primarily to aerial bombs and more particularly to aerial bombs of the time delay type which may be shot from a shotgun, for example.
Aerial bombs of the general type to which the present invention pertains are known in the art and embody a variety of structures. Typically, such prior art devices comprise in part what is essentially a firecracker or projectile with an attached fuse. The fuse extends from the base of the projectile through a washer or wad to a percussion element or mass of propellant charge, with all of the above elements packed in a conventional shotgun shell. When the percussion cap or primer on the shotgun shell base is detonated, the percussion element or propellant charge is ignited and in turn ignites the fuse on the firecracker or projectile. The projectile is propelled out of the shotgun shell casing and explodes a few seconds later at a location away from the original shotgun shell detonation.
Such aerial bombs may be used to remove birds or other animals from an area without subjecting the animals to any substantial risk of harm. Such birds or other animals are hopefully scared away from the area by the explosion of the firecracker or projectile and flee for safety, thus ridding an airplane pilot or a farmer, for example, of annoying or even dangerous pests.
Many of the prior devices of the type described suffer from a number of shortcomings. Such devices are frequently relatively complicated in construction, expensive to manufacture, and require precise positioning of a relatively large number of parts. The typical ignition fuse of the previously known devices extends longitudinally from the base of the projectile like a firecracker fuse and is often damaged in manufacture or assembly so as to cause a potential danger of premature explosion within the barrel of the shotgun or short bursts outside the barrel. The lack of uniformity in the fuse extensions also detracts from the desired uniform timing of the aerial bomb explosion. The prior art washers or wads are typically made of relatively heavy or rigid materials which suffer from significant resistance during travel through the shotgun barrel. Also, if the projectile itself is too large, it too may experience excessive barrel resistance and a consequent presssure build-up in the barrel which may cause premature explosion. Finally, if the projectile is improperly installed during assembly with the means incorrectly oriented at the wrong end of the casing the projectile will not explode after being propelled from the shotgun barrel.
Accordingly, it is an object of the present invention to provide an improved aerial bomb that is less complicated to properly construct and assemble than the prior art devices, thereby providing additional assurance of proper and uniform firing and providing additional protection against wad or projectile obstructions, barrel explosions, or short bursts.
In general, an aerial bomb according to the present invention comprises a shotgun shell hull or casing, a base for the shotgun shell hull enclosing one end thereof, and a shotshell primer. A mass of propellant powder is disposed in the shotgun shell hull adjacent the base and is in contact with the shotshell primer. An annular, wad packed adjcent the propellant powder charge, has a diameter sufficient to maintain continuous peripheral contact with the adjacent inner surface of the shotgun shell casing and includes an opening extending therethrough. A projectile located inside the shotgun shell hull includes a tube having two open ends and a diameter sufficiently smaller than the inner diameter of the shotgun shell casing to prevent continuous peripheral contact between the tube and the casing. The projectile further includes a fuse packed in the end of the tube communicating with the wad, an explosive charge within the tube, and a cap or other closure means on the opposite end of the tube. The end of the shotgun shell casing opposite the base is releasably closed to retain its contents until initial firing in the shotgun.
Upon initial firing hot gases from the ignited propellant powder pass through the hole in the wad to ignite the projectile fuse. The projectile is thereby expelled from the shotgun shell casing and the barrel and explodes several seconds later. Both the initial explosion and the delayed explosion may be used to frighten away undesirable birds or other animals without subjecting them to significant risk of harm.
According to the invention, the hull or casing of the aerial bomb includes means for permitting visual observation of position indicator means located on the projectile inside the casing. Such visual observation means allows quick and convenient inspection of one or more assembled aerial bomb devices to determine whether the projectile has been properly installd in the casing. In the preferred embodiment, the casing is composed of a substantially transparent, semi-transparent or translucent material, and the cap of the projectile has a color that contrasts with the remainder of the projectile, or at least contrasts with the fuse end of the projectile. Thus, by merely looking through the closed end of the casing, one may readily determine whether the cap end of the preferred projectile is properly positioned at the closed end of the casing and accordingly, that the projectile fuse is positioned adjacent the base end of the casing.
Additional advantages and features of the present invention will become apparent from the following description and the appended claims taken in conjunction with the accompanying drawings.